// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "ui/base/accelerators/accelerator.h"

#include <stdint.h>

#include "base/i18n/rtl.h"
#include "base/logging.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "build/build_config.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/events/event.h"
#include "ui/strings/grit/ui_strings.h"

#if defined(OS_WIN)
#include <windows.h>
#endif

#if !defined(OS_WIN) && (defined(USE_AURA) || defined(OS_MACOSX))
#include "ui/events/keycodes/keyboard_code_conversion.h"
#endif

namespace ui {

namespace {

    const int kEventFlagsMask = ui::EF_SHIFT_DOWN | ui::EF_CONTROL_DOWN | ui::EF_ALT_DOWN | ui::EF_COMMAND_DOWN;

} // namespace

Accelerator::Accelerator()
    : key_code_(ui::VKEY_UNKNOWN)
    , type_(ui::ET_KEY_PRESSED)
    , modifiers_(0)
    , is_repeat_(false)
{
}

Accelerator::Accelerator(KeyboardCode keycode, int modifiers)
    : key_code_(keycode)
    , type_(ui::ET_KEY_PRESSED)
    , modifiers_(modifiers)
    , is_repeat_(false)
{
}

Accelerator::Accelerator(const KeyEvent& key_event)
    : key_code_(key_event.key_code())
    , type_(key_event.type())
    , modifiers_(MaskOutKeyEventFlags(key_event.flags()))
    , is_repeat_(key_event.is_repeat())
{
}

Accelerator::Accelerator(const Accelerator& accelerator)
{
    key_code_ = accelerator.key_code_;
    type_ = accelerator.type_;
    modifiers_ = accelerator.modifiers_;
    is_repeat_ = accelerator.is_repeat_;
    if (accelerator.platform_accelerator_.get())
        platform_accelerator_ = accelerator.platform_accelerator_->CreateCopy();
}

Accelerator::~Accelerator()
{
}

// static
int Accelerator::MaskOutKeyEventFlags(int flags)
{
    return flags & kEventFlagsMask;
}

Accelerator& Accelerator::operator=(const Accelerator& accelerator)
{
    if (this != &accelerator) {
        key_code_ = accelerator.key_code_;
        type_ = accelerator.type_;
        modifiers_ = accelerator.modifiers_;
        is_repeat_ = accelerator.is_repeat_;
        if (accelerator.platform_accelerator_.get())
            platform_accelerator_ = accelerator.platform_accelerator_->CreateCopy();
        else
            platform_accelerator_.reset();
    }
    return *this;
}

bool Accelerator::operator<(const Accelerator& rhs) const
{
    if (key_code_ != rhs.key_code_)
        return key_code_ < rhs.key_code_;
    if (type_ != rhs.type_)
        return type_ < rhs.type_;
    return modifiers_ < rhs.modifiers_;
}

bool Accelerator::operator==(const Accelerator& rhs) const
{
    if ((key_code_ == rhs.key_code_) && (type_ == rhs.type_) && (modifiers_ == rhs.modifiers_))
        return true;

    bool platform_equal = platform_accelerator_.get() && rhs.platform_accelerator_.get() && platform_accelerator_.get() == rhs.platform_accelerator_.get();

    return platform_equal;
}

bool Accelerator::operator!=(const Accelerator& rhs) const
{
    return !(*this == rhs);
}

bool Accelerator::IsShiftDown() const
{
    return (modifiers_ & EF_SHIFT_DOWN) != 0;
}

bool Accelerator::IsCtrlDown() const
{
    return (modifiers_ & EF_CONTROL_DOWN) != 0;
}

bool Accelerator::IsAltDown() const
{
    return (modifiers_ & EF_ALT_DOWN) != 0;
}

bool Accelerator::IsCmdDown() const
{
    return (modifiers_ & EF_COMMAND_DOWN) != 0;
}

bool Accelerator::IsRepeat() const
{
    return is_repeat_;
}

base::string16 Accelerator::GetShortcutText() const
{
    int string_id = 0;
    switch (key_code_) {
    case ui::VKEY_TAB:
        string_id = IDS_APP_TAB_KEY;
        break;
    case ui::VKEY_RETURN:
        string_id = IDS_APP_ENTER_KEY;
        break;
    case ui::VKEY_ESCAPE:
        string_id = IDS_APP_ESC_KEY;
        break;
    case ui::VKEY_SPACE:
        string_id = IDS_APP_SPACE_KEY;
        break;
    case ui::VKEY_PRIOR:
        string_id = IDS_APP_PAGEUP_KEY;
        break;
    case ui::VKEY_NEXT:
        string_id = IDS_APP_PAGEDOWN_KEY;
        break;
    case ui::VKEY_END:
        string_id = IDS_APP_END_KEY;
        break;
    case ui::VKEY_HOME:
        string_id = IDS_APP_HOME_KEY;
        break;
    case ui::VKEY_INSERT:
        string_id = IDS_APP_INSERT_KEY;
        break;
    case ui::VKEY_DELETE:
        string_id = IDS_APP_DELETE_KEY;
        break;
    case ui::VKEY_LEFT:
        string_id = IDS_APP_LEFT_ARROW_KEY;
        break;
    case ui::VKEY_RIGHT:
        string_id = IDS_APP_RIGHT_ARROW_KEY;
        break;
    case ui::VKEY_UP:
        string_id = IDS_APP_UP_ARROW_KEY;
        break;
    case ui::VKEY_DOWN:
        string_id = IDS_APP_DOWN_ARROW_KEY;
        break;
    case ui::VKEY_BACK:
        string_id = IDS_APP_BACKSPACE_KEY;
        break;
    case ui::VKEY_F1:
        string_id = IDS_APP_F1_KEY;
        break;
    case ui::VKEY_F11:
        string_id = IDS_APP_F11_KEY;
        break;
    case ui::VKEY_OEM_COMMA:
        string_id = IDS_APP_COMMA_KEY;
        break;
    case ui::VKEY_OEM_PERIOD:
        string_id = IDS_APP_PERIOD_KEY;
        break;
    case ui::VKEY_MEDIA_NEXT_TRACK:
        string_id = IDS_APP_MEDIA_NEXT_TRACK_KEY;
        break;
    case ui::VKEY_MEDIA_PLAY_PAUSE:
        string_id = IDS_APP_MEDIA_PLAY_PAUSE_KEY;
        break;
    case ui::VKEY_MEDIA_PREV_TRACK:
        string_id = IDS_APP_MEDIA_PREV_TRACK_KEY;
        break;
    case ui::VKEY_MEDIA_STOP:
        string_id = IDS_APP_MEDIA_STOP_KEY;
        break;
    default:
        break;
    }

    base::string16 shortcut;
    if (!string_id) {
#if defined(OS_WIN)
        // Our fallback is to try translate the key code to a regular character
        // unless it is one of digits (VK_0 to VK_9). Some keyboard
        // layouts have characters other than digits assigned in
        // an unshifted mode (e.g. French AZERY layout has 'a with grave
        // accent' for '0'). For display in the menu (e.g. Ctrl-0 for the
        // default zoom level), we leave VK_[0-9] alone without translation.
        wchar_t key;
        if (key_code_ >= '0' && key_code_ <= '9')
            key = static_cast<wchar_t>(key_code_);
        else
            key = LOWORD(::MapVirtualKeyW(key_code_, MAPVK_VK_TO_CHAR));
        shortcut += key;
#elif defined(USE_AURA) || defined(OS_MACOSX)
        const uint16_t c = DomCodeToUsLayoutCharacter(
            UsLayoutKeyboardCodeToDomCode(key_code_), false);
        if (c != 0)
            shortcut += static_cast<base::string16::value_type>(base::ToUpperASCII(c));
#endif
    } else {
        shortcut = l10n_util::GetStringUTF16(string_id);
    }

    // Checking whether the character used for the accelerator is alphanumeric.
    // If it is not, then we need to adjust the string later on if the locale is
    // right-to-left. See below for more information of why such adjustment is
    // required.
    base::string16 shortcut_rtl;
    bool adjust_shortcut_for_rtl = false;
    if (base::i18n::IsRTL() && shortcut.length() == 1 && !base::IsAsciiAlpha(shortcut[0]) && !base::IsAsciiDigit(shortcut[0])) {
        adjust_shortcut_for_rtl = true;
        shortcut_rtl.assign(shortcut);
    }

    if (IsShiftDown())
        shortcut = l10n_util::GetStringFUTF16(IDS_APP_SHIFT_MODIFIER, shortcut);

    // Note that we use 'else-if' in order to avoid using Ctrl+Alt as a shortcut.
    // See http://blogs.msdn.com/oldnewthing/archive/2004/03/29/101121.aspx for
    // more information.
    if (IsCtrlDown())
        shortcut = l10n_util::GetStringFUTF16(IDS_APP_CONTROL_MODIFIER, shortcut);
    else if (IsAltDown())
        shortcut = l10n_util::GetStringFUTF16(IDS_APP_ALT_MODIFIER, shortcut);

    if (IsCmdDown()) {
#if defined(OS_MACOSX)
        shortcut = l10n_util::GetStringFUTF16(IDS_APP_COMMAND_MODIFIER, shortcut);
#elif defined(OS_CHROMEOS)
        shortcut = l10n_util::GetStringFUTF16(IDS_APP_SEARCH_MODIFIER, shortcut);
#else
        NOTREACHED();
#endif
    }

    // For some reason, menus in Windows ignore standard Unicode directionality
    // marks (such as LRE, PDF, etc.). On RTL locales, we use RTL menus and
    // therefore any text we draw for the menu items is drawn in an RTL context.
    // Thus, the text "Ctrl++" (which we currently use for the Zoom In option)
    // appears as "++Ctrl" in RTL because the Unicode BiDi algorithm puts
    // punctuations on the left when the context is right-to-left. Shortcuts that
    // do not end with a punctuation mark (such as "Ctrl+H" do not have this
    // problem).
    //
    // The only way to solve this problem is to adjust the string if the locale
    // is RTL so that it is drawn correctly in an RTL context. Instead of
    // returning "Ctrl++" in the above example, we return "++Ctrl". This will
    // cause the text to appear as "Ctrl++" when Windows draws the string in an
    // RTL context because the punctuation no longer appears at the end of the
    // string.
    //
    // TODO(idana) bug# 1232732: this hack can be avoided if instead of using
    // views::Menu we use views::MenuItemView because the latter is a View
    // subclass and therefore it supports marking text as RTL or LTR using
    // standard Unicode directionality marks.
    if (adjust_shortcut_for_rtl) {
        int key_length = static_cast<int>(shortcut_rtl.length());
        DCHECK_GT(key_length, 0);
        shortcut_rtl.append(base::ASCIIToUTF16("+"));

        // Subtracting the size of the shortcut key and 1 for the '+' sign.
        shortcut_rtl.append(shortcut, 0, shortcut.length() - key_length - 1);
        shortcut.swap(shortcut_rtl);
    }

    return shortcut;
}

} // namespace ui
